GENEVA – A United Nations special investigator says his reputation is being smeared and he won't resign, despite calls for his ouster over provocative remarks on terrorism, the United States and Israeli policy.

Richard Falk, the U.N. special rapporteur on human rights in the Palestinian territories, told reporters Tuesday in Geneva that he is only doing his job and "it's important to distinguish criticism from this kind of smear campaign."

In public remarks and reports sharply critical of Israeli settlement policy, Falk has repeatedly run afoul of advocacy groups such as U.N. Watch, which accuses him of anti-Semitism, and the United States, which called for his resignation.

U.N. Secretary-General Ban Ki-moon also rejected Falk's written commentary suggesting the Boston marathon bombings could be explained in part as resistance to "American global domination."